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Comment by Dr. Krishna Kumari Challa on February 15, 2022 at 11:45am

Research team finds clue to possible extraterrestrial origin of peptides

Researchers have discovered a new clue in the search for the origin of life, by showing that peptides can form on dust under conditions such as those prevailing in outer space. These molecules, which are one of the basic building blocks of all life, may therefore not have originated on our planet at all, but possibly in cosmic molecular clouds.

All life as we know it consists of the same chemical building blocks. These include peptides, which perform various completely different functions in the body—transporting substances, accelerating reactions or forming stabilizing scaffolds in cells. Peptides consist of individual amino acids arranged in a specific order. The exact order determines a peptide's eventual properties.

How these versatile biomolecules came into being is one of the questions about the origin of life. Amino acids, nucleobases and various sugars found in meteoroids, for example, show that this origin could be extraterrestrial in nature. However, for a peptide to be formed from individual amino acid molecules requires very special conditions that were previously assumed to be more likely to exist on Earth.

Water plays an important role in the conventional way in which peptides are created. Quantum chemical calculations have now shown that the amino acid glycine can be formed through a chemical precursor—called an amino ketene—combining with a water molecule. Put simply: In this case, water must be added for the first reaction step, and water must be removed for the second.

With this knowledge, the researchers  has now been able to demonstrate a reaction pathway that can take place under cosmic conditions and does not require water.

In an ultra-high vacuum chamber, substrates that serve as a model for the surface of dust particles were brought together with carbon, ammonia and carbon monoxide at about one quadrillionth of normal air pressure and minus 263 degrees Celsius. Investigations showed that under these conditions, the peptide polyglycine was formed from the simple chemicals. In this experiment, the German team was also able to detect the suspected amino ketene.

Now that it is clear that not only amino acids, but also peptide chains, can be created under cosmic conditions, we may have to look not only to Earth but also more into space when researching the origin of life.

S. A. Krasnokutski, K.-J. Chuang, C. Jäger, N. Ueberschaar, Th. Henning, "A pathway to peptides in space through the condensation of atomic carbon", Nature Astronomy (2022), DOI: 10.1038/s41550-021-01577-9

https://researchnews.cc/news/11610/Research-team-finds-clue-to-poss...

Comment by Dr. Krishna Kumari Challa on February 15, 2022 at 10:47am

Global study finds the extent of pharmaceutical pollution in the world's rivers

A new study looking at the presence of pharmaceuticals in the world's rivers found concentrations at potentially toxic levels in more than a quarter of the locations studied.

The new study looked at 258 rivers across the globe to measure the presence of 61 pharmaceuticals, such as carbamazepine, metformin and caffeine. The researchers studied rivers in over half of the world's countries—with rivers in 36 of these countries having never previously been monitored for pharmaceuticals.

With their latest study, the researchers found that:

• pharmaceutical pollution is contaminating water on every continent
• strong correlations between the socioeconomic status of a country and higher pollution of pharmaceuticals in its rivers (with lower-middle income nations the most polluted)
• high levels of pharmaceutical pollution was most positively associated with regions of high median age as well as high local unemployment and poverty rates
• the most polluted countries and regions of the world are the ones that have been researched the least (namely sub-saharan Africa, South America and parts of southern Asia).
• the activities most associated with the highest levels of pharmaceutical pollution included rubbish dumping along river banks, inadequate wastewater infrastructure and pharmaceutical manufacturing, and the dumping of the contents of residual septic tanks into rivers.

The study revealed that a quarter of the sites contained contaminants (such as sulfamethoxazole, propranolol, ciprofloxacin and loratadine) at potentially harmful concentrations.

The researchers hope that by increasing the monitoring of pharmaceuticals in the environment, they can develop strategies to limit the effects potentially caused by the presence of pollutants.

 Pharmaceutical pollution of the world's rivers, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2113947119.

The data for specific rivers will be available in the supplemental information associated with the publication (via PNAS). It will also be published on the Global Monitoring of Pharmaceuticals Project website.

https://phys.org/news/2022-02-global-extent-pharmaceutical-pollutio...

Comment by Dr. Krishna Kumari Challa on February 15, 2022 at 10:38am

Scientists discover how galaxies can exist without dark matter

In a new Nature Astronomy study, an international team led by astrophysicists from the University of California, Irvine and Pomona College report how, when tiny galaxies collide with bigger ones, the bigger galaxies can strip the smaller galaxies of their dark matter—matter that we can't see directly, but which astrophysicists think must exist because, without its gravitational effects, they couldn't explain things like the motions of a galaxy's stars.

It's a mechanism that has the potential to explain how galaxies might be able to exist without dark matter—something once thought impossible.

The team found seven galaxies devoid of dark matter. After several collisions with neighboring galaxies 1,000-times more massive, they were stripped of most of their material, leaving behind nothing but stars and some residual dark matter.

Jorge Moreno, Galaxies lacking dark matter produced by close encounters in a cosmological simulation, Nature Astronomy (2022). DOI: 10.1038/s41550-021-01598-4. www.nature.com/articles/s41550-021-01598-4

https://phys.org/news/2022-02-scientists-galaxies-dark.html?utm_sou...

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 10:05am

It's thought that IOH is caused by an opening of the blood vessels, triggered by the process of standing up. What these exercises might be doing, then, is counteracting that response, and the researchers say the two exercises could also be used in tandem.

Right now, those who experience IOH – thought to be up to 40 percent of the general population in the US – don't have any specific treatments available. Up until now, the best advice has been to try to stand up as slowly and as gradually as possible.

Although the sample size in this study was a small one and only involved women, these exercises could potentially change that situation. A little light-headedness might not seem like a huge problem, but it impacts daily life and can, in some cases, lead to fainting and a loss of consciousness.

https://www.heartrhythmjournal.com/article/S1547-5271(21)02524-8/fulltext

https://www.sciencealert.com/simple-muscle-exercises-can-help-reduc...

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 10:03am

Two Simple Muscle Exercises Can Help Reduce Dizziness When Standing Up

Feeling dizzy or light-headed when standing is a common experience caused by a drop in blood pressure. When this blood pressure dip is very brief and rapid, and not tied to any other health problems, it's referred to as initial orthostatic hypotension or IOH.

New research suggests some simple muscle exercises before or after standing could limit the effects of IOH, bringing relief to those who experience it, with no cost and no drugs involved. The key, it seems, is activating the lower body muscles before or after standing.

While researchers tested the muscle-tensing idea before – after people already stood up – with some success, this new study looked at whether it could work as a pre-emptive measure.

These are simple, effective, and cost-free interventions that patients can use to prevent their symptoms from IOH

The study involved 22 young women with a history of IOH, and two exercises were tested: repeatedly raising the knees while sitting for 30 seconds before standing and crossing the legs for 30 seconds after standing.

Researchers monitored the participants' heart rate and blood pressure during the experiments, with intervals between each one. Participants were also asked to self-report on the symptoms of IOH, including feelings of dizziness.

Compared with no intervention measures – so simply standing up as normal – both exercises made a significant difference in limiting the temporary drop in blood pressure and relieving the symptoms of IOH.

Since it is a physical maneuver, it simply requires the lower body limbs, which patients can utilize at any time and from anywhere to combat their symptoms

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 9:16am

Blood clot testing using smartphones

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 9:11am

The researchers suspect that bottle manufacturers only add a small proportion of the substances found intentionally. The majority have inadvertently occurred either during the production process or during use, where substances may have been converted from other substances. This includes the presence of the mosquito repellent DEET, where the researchers hypothesize that as one of the plastic softeners degrades, it is converted into DEET.

But even of the known substances that manufacturers deliberately add, only a tiny fraction of the toxicity has been studied. So, as a consumer, you don't know if any of the others have a detrimental effect on your health.

The study results were published in the Journal of Hazardous Materials.

1. Selina Tisler, Jan H. Christensen. Non-target screening for the identification of migrating compounds from reusable plastic bottles into drinking water. Journal of Hazardous Materials, 2022; 429: 128331 DOI: 10.1016/j.jhazmat.2022.128331

https://researchnews.cc/news/11590/Reusable-plastic-bottles-shown-t...

Part2

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 9:10am

Reusable plastic bottles shown to release hundreds of chemicals

Researchers  have found several hundred different chemical substances in tap water stored in reusable plastic bottles. Several of these substances are potentially harmful to human health. There is a need for better regulation and manufacturing standards for manufacturers, according to the chemists behind the study.

Have you ever experienced the strange taste of water after it has been in a reusable plastic bottle for a while? It appears that there is a solid, yet worrying reason for this.

Chemists  have studied which chemical substances are released into liquids by popular types of soft plastic reusable bottles. The results were quite a surprise.

The researchers were taken aback by the large amount of chemical substances they found in water after 24 hours in the bottles. There were hundreds of substances in the water—including substances never before found in plastic, as well as substances that are potentially harmful to health. After a dishwasher cycle, there were several thousand.

They  detected more than 400 different substances from the bottle plastic and over 3,500 substances derived from dishwasher soap. A large portion of these are unknown substances that the researchers have yet to identify. But even of the identified chemicals, the toxicity of at least 70 % remains unknown.

Photo-initiators are among the toxic substances in the water which worry the researchers. These are known to have potentially harmful effects on health in organisms, such as being endocrine disruptors and carcinogens. Furthermore, the researchers found a variety of plastic softeners, antioxidants and release agents used in the manufacture of the plastic, as well as Diethyltoluamide (DEET), commonly known as the active substance in mosquito spray.

Machine washing adds more substances into the bottled water
In their experiments, the researchers mimicked the ways in which many people typically use plastic drinks bottles. People often drink water that has been kept in bottles for several hours. The researchers left ordinary tap water in both new and used drinking bottles for 24 hours, both before and after machine washing, as well as after the bottles had been in the dishwasher and rinsed thoroughly in tap water.

What is released most after machine washing are the soap substances from the surface. Most of the chemicals that come from the water bottle itself remain after machine washing and extra rinsing. The most toxic substances that we identified actually came after the bottle had been in the dishwasher—presumably because washing wears down the plastic and thereby increases leaching. In new reusable bottles, close to 500 different substances remained in the water after an additional rinse. Over 100 of these substances came from the plastic itself.

Just because these substances are in the water, doesn't mean that the water is toxic and affects us humans. But the problem is, is that we just don't know. And in principle, it isn't all that great to be drinking soap residues or other chemicals.

Part1

Comment by Dr. Krishna Kumari Challa on February 14, 2022 at 8:49am

Space weather took out 40 SpaceX satellites, and it could get worse

SpaceX can mitigate the risk to its satellites my monitoring space weather in real time, but an increasingly active Sun and the large number of satellites in orbit won’t make it easy!

SpaceX just lost 40 of its newest satellites to a geomagnetic storm caused by solar radiation, a hazard that will only increase for Elon Musk’s company and other satellite operators over the coming few years.

SpaceX launched its latest batch of 49 Starlink satellites on 3 February, the latest in a constellation of more than 1900 small satellites providing broadband internet connectivity from low Earth orbit. On 4 February, a mass of charged particles ejected from the sun in late January reached Earth, dumping their energy into the planet’s magnetic field and increasing the density of the upper atmosphere.

Satellites launched into low Earth orbit always contend with some amount of atmospheric drag, but in a statement released 8 February, SpaceX noted the drag produced by the geomagnetic storm was 50% higher than in earlier launches. The company acknowledged that the drag was too much for 40 of the 49 satellites, which have reentered or will soon reenter the Earth’s atmosphere.

https://www.independent.co.uk/space/spacex-satellites-geomagnetic-s...

Comment by Dr. Krishna Kumari Challa on February 12, 2022 at 8:53am

Lifetime of knowledge can clutter memories of older adults, researchers suggest

When a person tries to access a memory, their brain quickly sifts through everything stored in it to find the relevant information. But as we age, many of us have difficulty retrieving memories. In a review publishing in the journal Trends in Cognitive Sciences on February 11, researchers propose an explanation for why this might be happening: the brains of older adults allocate more space to accumulated knowledge and have more material to navigate when attempting to access memories. While this wealth of prior knowledge can make memory retrieval challenging, the researchers say it has its upsides—this life experience can aid with creativity and decision-making.

Researchers looked at several behavioral and neuroimaging studies, which show that older adults have difficulty suppressing information that is no longer relevant and that when searching for a specific memory, they often retrieve other, irrelevant memories along with it. The studies also showed that when given a cognitive task, older adults rely more heavily on previous knowledge than younger adults do.

While the researchers focus primarily on the difficulties that these cluttered memories may pose, they also highlight a few situations in which these crowded memoryscapes may be useful. "Evidence suggests that older adults show preserved, and at times enhanced, creativity as a function of enriched memories," the researchers write. They further hypothesize that older adults may be well served by their prior knowledge when it comes to decision-making, where they can pull on their accumulated wisdom.

With continued study and increased understanding of how memory works in older adults, researchers are hopeful that they may be able to find new ways to help them. It is possible that the increased binding and richer encodings of older adults can even be leveraged to improve older adults' learning and memory.

Trends in Cognitive Sciences, Amer: "Cluttered memory representations shape cognition in old age" www.cell.com/trends/cognitive- … 1364-6613(21)00310-7 , DOI: 10.1016/j.tics.2021.12.002

https://medicalxpress.com/news/2022-02-lifetime-knowledge-clutter-m...

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